Diagnostics of nanoheterostructures by admittance methods

Head of the laboratory: Prof. A.V. Zubkov

Advanced methods of heterostructure characterization are of vital importance for modern high-tech fabrication of ultra bright light-emitted diodes based on InGaN/GaN-MQW. Created in SPb ETU resource center is devoted to diagnostics of AIIIBV and AIIIN heterostructures by various electrical and optical methods, including admittance spectroscopy, luminescence, electrochemical profiling and atomic-force microscopy.

Admittance is a complex value consisted of an imagine part (proportional to capacitance) and a real part (proportional to conductance, or simply current). So, admittance spectroscopy combines advantages of both capacitance and current technics.

By scanning different electric parameters of p-n junction or Schottky barrier, available in admittance measurements, as function of temperature, applied bias and the frequency of the bias, one can propose a wide set of methods for precise quantitative characterization of semiconductor materials and structures.